1.13V <115C (RIP CPU)
1.22V <110C (really not recommended)
1.315V <100C (not recommended)
1.36V <90C (not recommended)
1.39V <80C
1.42V <70C
1.445V <60C
1.465V <50C
1.475V <40C
1.485V <30C
1.49V <20C*
1.495V <10C*
1.50V <0C*
^ Package temps in cb20.
Take off 20mv if your motherboard is bad.
* 20C and lower is very conservatively estimated and not compiled of actual real data. Use at your own risk.
Random other things that are related.
Highest I recommend for benchmarking is 1.5V. Do not blame me if your CPU dies though. My friend ran a 8350k at 1.52V for 2hours at 5.53ghz and it didn't degrade. My other friend ran a 7600k at 1.535V 5.36ghz for 1 hour until it crashed due to degradation. (Not software readings, actual hardware ones) (I'm saying 1.5 and not 1.52 because every CPU is different and I like to be safe.) Edit > Due to confusion on this point I must add that 1.5V isn't safe for much time at all. Only run this if you really want that amazing cinebench score or something. No longer then 6 hours.
To all you people running 1.45V, this isn't Sandy bridge, you can't run 1.45V at 80C for 9+ years on skylake. Please acknowledge this.
If anyone has had a skylake, kabylake or coffee lake CPU die at any listed settings, please inform me so I can update this list (does not include people running trash motherboards).
If you want to tell me that these numbers are too conservative, I really couldn't care less because being safe is more important then being clocked 100mhz higher.